When I met up with Shoot ‘Em Up star Paul Giamatti recently, he told me Vince Vaughn his co-star in Fred Claus, tends to be spontaneous.

“He doesn’t like to use scripts. He likes to go off the script a lot, which was fun and took a little getting used to, but once I got used to it, it was great.”

What’s the story behind the movie?

“Vince Vaughn plays Santa Claus’ screw-up brother who needs a job, so his brother gives him a job,” Paul says. “The idea is Santa Claus is a stressed-out CEO. He’s got a jolly persona he has to keep up all the time.”

Who does Paul play? Why Santa, of course. The holiday flick will be out in November.